Results 31 to 40 of about 353 (134)

A Search for Asymmetric Kinematic Components in Circumstellar Envelopes Using OH Main Line Masers

open access: yesThe Astrophysical Journal
Circumstellar OH maser lines are useful for studying the dynamics of the circumstellar envelope (CSE) around evolved stars. This study aims to identify CSEs around cold stars, which exhibit deviations from the spherical expansion, by comparing the ...
Jia-Yong Xie   +2 more
doaj   +1 more source

Polarized Maser Emission with In-source Faraday Rotation

open access: yesThe Astrophysical Journal, 2023
We discuss studies of polarization in astrophysical masers with particular emphasis on the case where the Zeeman splitting is small compared to the Doppler profile, resulting in a blend of the transitions between magnetic substates.
T. L. Tobin, M. D. Gray, A. J. Kemball
doaj   +1 more source

Early Planet Formation in Embedded Disks (eDisk). XVII. A Compact but Structured Keplerian Disk and Large-scale Streamers Revealed in the Class I Protostellar System IRAS 04169+2702

open access: yesThe Astrophysical Journal
We present high-resolution (∼0 $\mathop{.}\limits^{^{\prime\prime} }$ 05; 8 au) dust continuum and molecular line observations toward the Class I protostellar system IRAS 04169+2702 in the Taurus B213 region, as part of the Atacama Large Millimeter ...
Ilseung Han   +24 more
doaj   +1 more source

ALMA’s Acute View of pPNe: Through the Magnifying Glass... and What We Found There

open access: yesGalaxies, 2018
We present recent Atacama Large Millimeter/submillimeter Array (ALMA)-based studies of circumstellar envelopes (CSEs) around Asymptotic Giant Branch (AGB) stars and pre-Planetary Nebulae (pPNe).
Carmen Sánchez Contreras   +3 more
doaj   +1 more source

Linear or Cyclic? Theoretical Investigation of Astrophysically Relevant Magnesium‐Bearing MgCnH Carbon Chains and Related Isomers

open access: yesJournal of Computational Chemistry, Volume 46, Issue 2, January 15, 2025.
The global minimum energy structure of astrophysically relevant MgCnH systems is linear when n is even, and cyclic when n is odd. ABSTRACT Magnesium‐containing molecules, including MgC2H, MgC4H, and MgC6H, have been detected in the interstellar medium, largely facilitated by their high dipole moments.
A. Karolyna M. S. Gomes   +3 more
wiley   +1 more source

Excited-state OH Masers in the Water Fountain Source IRAS 18460-0151

open access: yesThe Astrophysical Journal Letters
Water fountain objects are generally defined as evolved stars with low to intermediate initial mass accompanied by high-velocity molecular jets detectable in the 22.235 GHz H _2 O maser line.
Xu-Jia Ouyang   +5 more
doaj   +1 more source

First direct detection of large polycyclic aromatic hydrocarbons on asteroid (162173) Ryugu samples: An interstellar heritage

open access: yesNatural Sciences, Volume 4, Issue 4, October 2024.
Large free aromatic species, with up to 61 carbon atoms, were detected in grains of the Ryugu carbonaceous asteroid using ultra‐sensitive two‐step laser mass spectrometry. This discovery confirms the presence of large polycyclic aromatic hydrocarbons in the interstellar medium and provides new information on the formation and evolution of organic ...
Hassan Sabbah   +3 more
wiley   +1 more source

Gas-phase Molecules in Protoplanetary Nebulae with the 21 μm Emission Feature

open access: yesThe Astronomical Journal
It has been more than 30 years since the enigmatic 21 μ m emission feature was first discovered in protoplanetary nebulae (PPNs). Although dozens of different dust carrier candidates have been proposed, there is as yet no widely accepted one.
Jian-Jie Qiu   +8 more
doaj   +1 more source

The deep eclipses of RW Aur revisited by long‐term photometric and spectroscopic monitoring

open access: yesAstronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow‐up observations. We performed multiband (BVRI) photometry of the system with the Cassegrain‐Teleskop‐Kamera II and the ...
Oliver Lux   +2 more
wiley   +1 more source

Considerations on the Origin of IRAS 19312+1950 Based on Long-term Maser Observations

open access: yesThe Astrophysical Journal
IRAS source 19312+1950 (hereafter I19312) is an infrared point source with maser emissions of SiO, H _2 O, and OH molecules. Although initial observations suggested that I19312 might be an evolved star, its characteristics are not fully consistent with ...
Huan-Xue Feng   +7 more
doaj   +1 more source

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